The typical asking rate per listing is in the $20's per square foot per year. The Costa Mesa region is seeing a decline in rates. In the last 3 months, the median rate decreased $6 per sqft per year. That's a 19% decline in rent.
Compared to the rest of the Metropolitan Los Angeles market, the Costa Mesa region has smaller rates, so you should have no trouble finding a great deal in this depreciated region.
In the last 90 days, 36 listings have been posted online, which means leases most likley are going fast. You'll want to be prepared to make an offer immediately. About 3% of the available space in the Costa Mesa are subleases, so you will probably have to consider a longer term lease. There aren't many listings below 2,000 square feet available, so finding a space for a small business might be tough.
Even though the median size is 2,640 sqft, there are still 0 office spaces below 2,000 sqft. Most buildings in this region are around 2 floors. Most buildings in this market were built in 1982 and are Class A.